Sequential process optimization for a digital light processing system to minimize trial and error

Abstract

In additive manufacturing, logical and efficient workflow optimization enables successful production and reduces cost and time. These attempts are essential for preventing fabrication problems from various causes. However, quantitative analysis and integrated management studies of fabrication issues using a digital light processing (DLP) system are insufficient. Therefore, an efficient optimization method is required to apply several materials and extend the application of the DLP system. This study proposes a sequential process optimization (SPO) to manage the initial adhesion, recoating, and exposure energy. The photopolymerization characteristics and viscosity of the photocurable resin were quantitatively analyzed through process conditions such as build plate speed, layer thickness, and exposure time. The ability of the proposed SPO was confirmed by fabricating an evaluation model using a biocompatible resin. Furthermore, the biocompatibility of the developed resin was verified through experiments. The existing DLP process requires several trials and errors in process optimization. Therefore, the fabrication results are different depending on the operator’s know-how. The use of the proposed SPO enables a systematic approach for optimizing the process conditions of a DLP system. As a result, the DLP system is expected to be more utilized.

Development of digital light processing-based multi-material bioprinting for fabrication of heterogeneous tissue constructs

“…The porous structure of PDMS provided an oxygen inhibition layer between the glass slide and the cured bioink to inhibit radical polymerization and reduce the separation force. 43 The bioprinting system used an ultraviolet (UV) optical engine system (SF-4710, Shengfeng Tech, Shenzhen, China) as the light source, with a wavelength of 405 nm and an adjustable output UV intensity of 5.6–45.6 mW cm −2 , which projected the sliced images of the printed model from the bottom of the material vat. The cleaning system was comprised of an electric sprayer and a turbofan.…”

The rise of mechanical metamaterials: Auxetic constructs for skin wound healing

“…[130][131][132][133][134][135][136] In DLP applied to scaffold fabrication, a digital light projector is used to shine a pattern of light onto a photosensitive material solution, which contains a base-material, such as a hydrogel or a gelatin, and a photoinitiator, which reacts when exposed to the light, thus controlling the base-material solidification. 137 The light pattern is produced by a digital micromirror device (DMD) consisting of an array of micromirrors capable of changing their orientation via micro-actuators controlled by computer that allow them to reflect the light onto the material or onto an outer zone, where it is absorbed to prevent other surface reflections that could affect the precision of the fabrication process. 138 This precise control can be applied to obtain a wide range of shapes and geometries.…”

Poly(ethylene glycol)–Norbornene as a Photoclick Bioink for Digital Light Processing 3D Bioprinting

“…26 Added to these benefits is that the bioinks used in DLP 3DBP do not require high viscosity, permitting printing of a smooth surface with a fast printing speed. 29 A typical DLP printer is composed of an array of millions of micromirrors, each corresponding to a pixel in the displayed image and can be digitally modulated to design patterns to enable selective light penetration and cross-linking. Various photo-cross-linkable biomaterials with vinyl derivatives have been increasingly used for DLP 3DBP.…”

“…This contribution focuses on DLP 3DBP as it permits layer-by-layer or volumetric projection rather than point-by-point or line-by-line printing such as the case in SLA and extrusion printing formats . Added to these benefits is that the bioinks used in DLP 3DBP do not require high viscosity, permitting printing of a smooth surface with a fast printing speed …”